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US 10,895,182 B2Granted
Method and system for particulate filter regeneration
AssigneeFord Global Technologies, LLC
InventorsJohn Rollinger, Douglas Martin, Vincent Martinez
Life of this patent
Estimating the term…
Abstract
Methods and systems are provided for heating an exhaust particulate filter (PF) to enable filter generation. In one example, a method may include adjusting engine air fuel ratio and injecting secondary air flow upstream of the PF to increase PF temperature. The level of engine air fuel ratio adjustment and the amount of secondary air injection upstream of the PF may be adjusted to account for enrichment induced cooling at a three-way catalyst (TWC) positioned upstream of the PF.
Claims19
A method, comprising:
- routing exhaust gases from an engine through a three-way catalyst (TWC) and then through a gasoline particulate filter (GPF);
- controlling enrichment of the engine exhaust gases to be overall richer than stoichiometry at the GPF;
- injecting air into the GPF to create an exotherm with the enriched exhaust gases entering the GPF in response to the GPF having a temperature higher than a first threshold temperature of an oxidation temperature of particulate matter deposited on the GPF and lower than a second threshold temperature of an ignition temperature of air and fuel in an exhaust passage upstream of the GPF;
- and
- controlling a degree of the enrichment to reduce any induced cooling of the TWC caused by the enrichment.
2 more elements
A method, comprising:
- routing exhaust gases from an engine through an exhaust catalyst and then through a gasoline particulate filter (GPF);
- prior to exhaust catalyst light-off, adjusting engine air fuel ratio and injecting secondary air flow upstream of the exhaust catalyst;
- and
- after the exhaust catalyst light-off,
- in response to each of a higher than threshold particulate matter load on the GPF, and a lower than threshold GPF temperature, adjusting the engine air fuel ratio and injecting the secondary air flow upstream of the GPF to regenerate the GPF while maintaining an exhaust catalyst temperature above a light-off temperature, and maintaining the exhaust catalyst temperature above the light-off temperature by reducing the secondary air flow upstream of the GPF in response to the exhaust catalyst temperature reducing to below the light-off temperature.
2 more elements
An engine system, comprising:
- a controller with computer readable instructions stored on non-transitory memory to:
- during a first condition, increase exhaust temperature upstream of an exhaust catalyst coupled to an exhaust of an engine by enriching an air fuel ratio of an air and fuel mixture combusted by the engine, and/or spark timing of spark delivered to the engine for ignition of the air and fuel mixture, and injecting air upstream of the exhaust catalyst;
- and
- during a second condition, increase exhaust temperature upstream of an exhaust gasoline particulate filter (GPF) by enriching the engine air fuel ratio and injecting air upstream of the GPF, while maintaining an exhaust catalyst temperature above a first threshold temperature by reducing injected air flow upstream of the GPF in response to the exhaust catalyst temperature reducing to below a light-off temperature.
1 more element
Dependencies are inferred from the claim text.